A. Field of Invention
This invention pertains to a method and apparatus of enhancing a 3D movie by adding to it new content, such as subtitles, at a particular depth.
B. Description of the Prior Art
In the past, 3D movies or other episodic 3D content were recorded optically on film and then distributed in analog formats. However, advances in digital signal processing make it possible to provide such content in digital formats which have several well known advantages over the analog formats.
In the present application, the term ‘digital 3D movie’ is used to refer to 3D movies, episodic content, or other 3D multi-media content recorded, produced and/or converted into a digital format. This includes content produced in 2D and then post-produced from 2D to 3D, as well as rendered from 3D animation systems.
Digital 3D digital movies may be produced by converting the analog content (e.g., content recorded on film or analog video tape) into a desired digital format. Alternatively, digital video cameras are used to generate content in a raw digital format, which is then edited and converted into a format suitable for viewing or distribution. Different venues or distribution channels are used for distributing the digital 3D movie electronically, including:    A. Digital communication channel to movie house for theatrical presentation;    B. Satellite transmission to subscribers, such as DirecTV;    C. Blu-ray Disc;    D. DVD;    E. Various hand-held devices such as Nintendo 3DS® receiving streamed media over a wi-fi network or other private or public channels.
Each of these venues require typically its own format(s). For example, a satellite communication channel for digital projection in a movie theater the digital 3D movie in a JPEG 2000 format.
A Blu-ray 3D Disc normally uses MVC formatted files.
A DVD may require MPEG-2 format files.
Each of these digital 3D movie distribution channels may use different forms of 3D encoding, resolution, compression, and/or authoring. For example, theatrical presentation may require 4K resolution using JPEG2000 compression with ‘burned in’ subtitles for digital theatrical exhibition. A Blu-ray disc may require an image with 1920×1080 p HD resolution using MVC compression with subtitles presented in a ‘one plane+offset’ manner for Blu-ray Disc. DirecTV may require a frame compatible spatial compression (e.g. ‘side-by-side’) and AVC compression with ‘burned in’ subtitles for DirecTV satellite broadcast. A small, hand held device may require a 800×240 pixel image (400×240 for each eye) resolution using Mobiclip compression with ‘burned in’ subtitles for Nintendo 3DS autostereo (no glasses required) viewing.
Moreover, as previously mentioned, digital 3D movies in some of the formats may incorporate additional content, e.g., menus, subtitles in one or more languages, etc., using an appropriate authoring process.
Typically, once a digital 3D movie is made and recorded in a raw format, it is converted into a format suitable for a particular distribution channel, such as the channels described above. Depending upon the order in which a digital 3D movie is prepared for distribution, e.g. theatrical, Blu-ray Disc, DVD, satellite broadcast, there may be relevant 3D information determined by encoding or authoring software and/or an operator on a frame by frame, group of frames, or scene by scene basis and recorded in a respective log. For example, a Z-axis depth map of whole frames' content, or of objects of interest within frames, may be determined when preparing to position subtitles or other graphics in 3D space over the background video.
One problem with the existing techniques described above is that they are not used systematically to add new information, such as subtitles and/or other relevant graphics, to an existing 3D movie